JPH0229334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching an elastic member to sanitary articles such as disposable diapers and disposable diaper covers.

Conventionally, so-called pants-type disposable diapers have an elastic member attached to the part that contacts the leg area of the wearer in order to have good adhesion to the wearer's leg area and effectively prevent the leakage of excrement fluid. It is known from Japanese Patent Publication No. 52-40267 and has been put into practical use.

The method of attaching such an elastic member was also published in 1983.
This method is known and implemented in Publication No. 26219, etc. The method disclosed in this publication involves continuously pasting continuous elastic members that are intermittently glued to both sides of a continuous web while being stretched during the manufacturing process of a disposable diaper, and in the manufacturing completion process, the elastic members are At the same time, the continuous structure of the diaper is cut into individual diaper products, and at this time, the unstucked parts of the separated elastic members are contracted from the cut-off end of the product into the interior of the product. Accordingly, the contractile force of the elastic member is applied only to the area surrounding the legs of the product, and this is generally referred to as the snapback method of attaching the elastic member.

According to such a snapback method, since the cut-off end of the elastic member is allowed to contract, the contraction (retraction) path of the elastic member in the product cannot be joined, and the contracted end remains open. . As a result, there is a drawback that excretory fluid leaks from the open end when the product is worn.

The object of the present invention is to intermittently apply glue in advance in the longitudinal direction of a continuous web constituting a product, and then adhere a continuous elastic member under stretching through the glue,
Furthermore, by cutting the elastic member to the required length, the above-mentioned drawbacks can be solved, and the attachment of the elastic member to a disposable sanitary article can be carried out continuously in the same manner as the snap-back method. The purpose is to provide a method.

The embodiments of the method of the present invention will be described below with reference to illustrated examples.

FIG. 1 is a side view showing a general mechanism for carrying out the method of the present invention.

A continuous back web 2 such as a synthetic resin film is sent out from a roll 1 and sent to a first nip roll 7 via guide rolls 3 to 6. On the other hand, a continuous elastic member 8 made of a plurality of rubber threads is sent to the first nip roll 7 via a guide roll 9. In the process of sending the elastic member 8 to the first nip roll 7, the take-up speed of the nip roll is set several times higher than the delivery speed of the elastic member 8, which is regulated by the guide roll 9, so that the elastic member 8 is expanded to the required magnification. be done. Gluing means 10 disposed between the feed paths of the back web 2 intermittently applies glue to the web. In the first nip roll 7, the elastic member 8 is integrally adhered to the back web 2 by the applied glue while maintaining the stretched state.

On the other hand, a substantially non-stretchable continuous presser tape 14 having a size that covers the elastic member 8 is fed from the roll 15 to the roll cutter 17 via the guide roll 16. The presser tape 14 is cut by a roll cutter 17 into a length corresponding to or slightly longer than the pasted length of the back web 2 (indicated by the symbol L in the second figure). Separated presser tape 14
is sent to the first nip roll 7 while being attracted to the outer periphery of the transfer vacuum roll 18 disposed between the roll cutter 17 and the first nip roll 7 .

The transfer vacuum roll 18 is synchronized with the feeding of the first nip roll 7, and the pressure tape 14, which is temporarily held on the circumferential surface of the vacuum roll 18 and cut off, is applied to the glued portion L of the back web 2 on the vacuum roll 18. The image is transferred by the roll 18 and pressed by the vacuum roll 18 and the first nip roll 7. At the same time, the adhesive applied to the back web 2 spreads between the back web 2 and the presser tape 14 due to this pressure bonding, so that the back web 2 and the presser tape 14 are also bonded together.

The back web 2 to which the elastic member 8 and the presser tape 14 are bonded in this way is maintained in a tensioned state when the ultrasonic cutter 12 is placed between the first nip roll 7 and the second nip roll 11 having the same speed. It passes through the receiving roll 13 and is sent to the second nip roll 11. The ultrasonic cutter 12 is located at the center of the portion where the glue is not applied, that is, where the elastic member 8 is not bonded to the back web 2 and where the presser tape 14 is not located (indicated by reference numeral l in the second figure). When the cutter is positioned at , the cutter is activated and an ultrasonic wave is emitted from it. The ultrasonic cutter 12 has an output end having substantially the same width as the elastic member 8 and faces the travel path of the elastic member 8, so that the corresponding portions of the elastic member 8 and the back web 2 that receive the ultrasonic waves are softened. Therefore, the contractile force of the portion l of the elastic member 8 in the stretched state is concentrated at the softening point and is cut, while the portion of the back web 2 on the lower surface thereof softens, but it is only at the extreme point of the back web 2. Since the tension force is not concentrated on this part, it remains in a softened state, and is cooled and hardened during movement after the operation of the ultrasonic cutter 12 is stopped. The elastic member 8 thus cut is
Said portion l that is not bonded to the back web 2
will contract as shown in FIG.

The back web 2 to which the elastic member 8 and the presser tape 14 are attached as described above is attached to the second nip roll 1.
1, it is laminated integrally with a continuous top web 26 that is fed to the roll. At this time, if necessary, the absorbent core 20 is placed between the webs 2 and 26, and a polymeric member 2 consisting of an elastic member 8 and a presser tape 14 bonded to both sides of the webs.
1 (see Fig. 2) and fixed with glue. The continuous article thus formed is separated into individual products at the center of the portion 1 where the overlapping member 21 is not located, as shown in FIG.

In FIG. 3, the specific relationship between the transfer vacuum roll 18 and the low cutter 17 for continuously attaching each presser tape 14 cut to a predetermined length to the back web 2 is illustrated. be.

In FIG. 3, a third nip roll 22 is placed in front of the roll cutter 17. The presser tape 14 is sent to the roll cutter 17 via the third nip roll 22. The roll cutter 17 has a blade 23 protruding from its circumferential surface, and a suction area 24 having a weak suction force that temporarily attracts the end of the presser tape 14 behind the blade 23 in the direction of rotation indicated by the arrow. is provided. The transfer vacuum roll 18 is provided with a suction area 25 having a suction force stronger than the suction force of the suction area 24 in an arcuate area corresponding to the length of the presser tape 14 to be cut. The feeding speed of the presser tape 14 is set lower than the rotational peripheral speed of the roll cutter 17 and the transfer vacuum roll 18.

Under such conditions, the tip of the presser tape 14 cut by the blade 23 becomes a free end, and as it rotates, it slides on the circumferential surface of the roll cutter 17 while apparently retreating by the aforementioned speed. The suction area 24 reaches a position (the state shown in the third figure) where it contacts the end area of the presser tape 14. This results in
The presser tape 14, whose leading end is still free, is weakly adsorbed by the suction area 24 at its slightly front end and slides by the speed difference, and the suction area 24 approaches the tip of the presser tape 14. In this state, when the starting end of the suction area 25 of the rotating transfer vacuum roll 18 comes into circular contact with the suction area 24 of the roll cutter 17, the presser tape 14 moves from the suction area 24 with a weak suction force to the suction area 24 with a strong suction force. Transfer to area 25. However, the holding tape 14 that is attracted to the suction area 25 continues to slide due to the speed difference, and continues to slide until the starting end of the suction area 25 comes into contact with the first nip roll 7 (shown in the first figure). When the transfer vacuum roll 18 rotates, the tip of the presser tape 14 reaches the starting end of the suction area 25, and immediately after that, the rotating blade 23 cuts off the presser tape 14, so that the separated presser tape 14 reaches the suction area 25. The adhesive is sent to the glued portion L (shown in the second figure) of the back web 2 on the first nip roll 7. In this way, the presser tape 14 is sequentially cut to the required length, and each cut-off presser tape 14 is sequentially, that is, intermittently pasted to the glued portion L with a time difference from the subsequent presser tape 14. .

The elastic member 8 is shown as being made of a plurality of thread-like rubber, and although this is preferred, it is also possible to use tape-like rubber or urethane. Also, as the presser tape 14,
Any material such as synthetic resin film, nonwoven fabric, paper, etc. may be used as long as it has substantially non-stretchability. Also, as the glue, a hot melt type glue is preferably used.

As described above, according to the method of the present invention, the continuous elastic member is cut by ultrasonic waves at the time of attachment to the continuous web, so that unnecessary parts as expansion/contraction parts are contracted in advance. It is unnecessary to provide a retraction path at the end of the elastic member by contraction of the end of the elastic member, and the end of the article can be sealed to prevent excrement from leaking.

Furthermore, according to the method of the present invention, the continuous press tape is cut to the required length and attached to the continuous web, so that the elastic member has no elongation holding power even though the adhesive for this purpose has not sufficiently hardened. Even if it is unraveled, it will not peel off from the web due to its shrinkage force. Therefore, it is possible to continuously attach the separated elastic members to the continuous web.

Furthermore, in the case of an article to which a presser tape is attached in this way, it is possible to reduce the local compressive force of the elastic member against the wearer's leg area so as not to cause pressure marks or pain around the leg area. I can do it.

[Brief explanation of drawings]

Fig. 1 is a side view showing an outline of an apparatus for carrying out the method of the present invention, Fig. 2 is a schematic plan view of a sanitary article processed by the method of the invention, and Fig. 3 is a transfer mechanism in the apparatus shown in Fig. 1. The schematic side view which shows an example. 2...back web, 7...first nip roll, 8
... Elastic member, 10... Gluing means, 11... Second nip roll, 12... Ultrasonic cutter, 13... Receiving roll, 14... Presser tape, 17... Roll cutter, 18... Transfer vacuum roll, 26... Top web.

Claims (1)

[Scope of Claims] 1. While feeding the continuous web to the first nip roll, glue is intermittently applied to the continuous web in the longitudinal direction thereof, and on the other hand, while feeding the continuous elastic member to the first nip roll, glue is applied in the longitudinal direction of the continuous web. while feeding a substantially non-stretchable continuous presser tape to a transfer vacuum roll that is in contact with the first nip roll, and attaching the tape to the continuous web through the glue; Cut the continuous web into a length approximately corresponding to the length of the glue-applied portion of the continuous web, and transfer the cutting tape to the glue-applied portion of the continuous web while holding it on the circumferential surface of the vacuum roll. The tape is then pressed by the first nip roll and the vacuum roll so that it adheres to the continuous elastic member located in the glue-applied portion of the continuous web, and by repeating this operation, the cutting presser tape is cut. The first continuous web is placed intermittently on the first continuous web.
The continuous web is fed to a second nip roll at the same speed as the nip roll, and then an ultrasonic cutter located between the first nip roll and the second nip roll is used to cut the continuous web without applying glue and with the cutting tape in place. A method for attaching an elastic member to a disposable sanitary article, comprising: cutting the continuous elastic member at a portion where the elastic member is not bonded to the continuous web via the glue, and shrinking the portion of the elastic member that is not bonded to the continuous web via the glue.